Liquid fuel burning apparatus



Jan. 16, 1934;

-w. J. sMH'H LIQUID FUEL BURNING APPARATUS I Filed June 24, 1931" 5Sheets-Sheet 1 r ATTORNEYS R o T N E V m Jan. 16, 1934. w J s n' LIQUIDFUEL BURNING APPARATUS Filed June 24, 1931 5 Sheets-Sheet 2 WI i/2INVENTOR r/Wo ATTQRNEYi Jan. 16, 1934. w. J. SMITH LIQUID FUEL BURNINGAPPARATUS Filed June 24. 1931 5 Sheets-Sheet 3 7 ATTORNEYS 61 INVENT R4/44 4. I BY Jan. 16, 1934. w. J. SMITH 1,943,532

LIQUID FUEL BURNING APPARATUS Filed June 24, 1931 5 Sheets-Sheet 4 F 13.INVEN OR W f Mb ATTORNEY5 .Jan. 16, 1934. w, J, SWTH 1,943,632

LIQUID FUEL BURNING APPARATUS Filed June 24, 1931 5 Sheets-Sheet 5 lentexplosion occurred.

Patented Jan. '16, 1934 UNITED STA LIQUID FUEL BURNING APPARATUS William#1. Smith, Lakewood, 01110, assignor to Cleveland. Steel ProductsCorporation, Cleveland, Ohio, a corporation of Ohio Application June 24,1931. No. 546,504

11 Claims. (Cl. 175-415) This invention relates to liquid fuel burningappa'ratus and more particularly to means for igniting the fuel. It iswell known that the best and most eflicient means for igniting liquidfuel is an electric spark but, in spite of this fact, no safe andpractical means for making use of the electric spark for igniting liquidfuel has been heretofore developed for use in connection with liquidfuelburnera-such as furnaces. In many types of liquid fuel burningdevices, especially those making use of a fuel distributing fan orblower, a fine mist of liquid fuel is discharged against a refractorymember and the fuel so collected on this member is ignited.

One'disadvantage heretofore encountered in the use of sparkgapelectrodes is that the elec-, trodes were not properly arranged withrespect to the hearth and would become shorted, due to carbon deposits,and when the demand was made for heat the liquid fuel gasified upon itscontact with the refractory member if it was hot and as a result whenthe electrodes eventually did spark upon the breakage of the carbondeposits, a vio- One of the objects of the present invention is toprovide spark ignition means for usein connection with liquid fuelburning apparatus which will function quickly and eflicientl y withoutdanger of explosions resulting from theiroperation.

Another object is to provide a liquid fuel burn-- ing apparatus with asimple and efllcient spark ignition means which can be economically pro-.duced and easily assembled.

Another object is to provide liquid fuel buming apparatus of the rotaryfuel discharge type with sparkignition means which will functionat alltimes during normal operation of the apparatus, and will produce anigniting spark at the proper location.

Another object is to provide liquid fuel burn? ing apparatus with aspark ignition means so arranged as to substantially eliminate thedifllculties heretofore encountered by reason of the ing certain of itselectrodes. mounted for substantial movement after the fuel. has beenignited. With the above and other objects in view, which will beapparent from the following deand shown in section to illustrate theapplication tailed description, the present invention consists incertain features of construction and combinations of parts which will bereadily understood by those skilled in the art to which the inventionappertains.

In the drawings, which illustrate suitable emm bodiments'of theinvention,

Figure 1 is a perspective view of a furnace construction, portions ofthe same being broken away of the present invention thereto;

Fig.2 is an enlarged fragmentary inner elevation of the hearth segmentshowing the spark ignition device attached thereto; a

Fi 3 is a fragmentary plan; view of the ap- To paratus shown in Fig. 2;

Fi 4 is a section taken substantially on line H of Fig. 3, the normalposition'of one of the ignition electrodes being shown in brokenoutline;

showing a modified mounting means for one of the electrodes, theoperative po'sition'of the electrode being shown in broken outline;

Fig. 12 is a section taken substantially on the line 12-12 of Fig. 11;Fig. 13 is atop plan view of a further modified mounting for one of theelectrodes;

Fig. 14 is a section taken on the line 1km of Fi 131',

Fig. 15 is a section through a hearth segment showing another meansofmounting the electrodes;

Fig. 16 is a Plan View of the apparatus shown in Fig. 15; and

Fig. 1'! is a transverse section through a hearth ring showing the useof further modified electrodes;

Referring to the accompanying drawings, in which likenumerals refer tolike parts throughout .the several views, the apparatus of the presentinvention is shown in connection with a-liquid fuel burning apparatus ofthe rotary fuel discharge type. It is to be understood, however, that*the present invention is adaptable to liquid fuel burning devices oftypes other than those shown in the drawings I In the type of liquidfuel burning apparatus showninl'lglmdtakenforthepurposeofib. lustration,the furnace 1 is provided with a continuous hearth segment 2 of suitablerefractory I Figs. '5 to 10, inclusive, are wiring diagrams "f materialwhichis supported well above the base of the structure'on a bed 3 ofrefractory material that .is carried by a hearth pan l. The hearth pan'4 extends completely across the furnace l and is suitably supported atits periphery.

In the construction shown, the hearth segment 2 is preformed and ispreferably provided with an endless channel or recess 5 of suitableshape which opens inwardly and upwardly to provide a suitable faceagainst which the liquid fuel may be discharged.

The liquid fuel is fed from a source of supply through control valves 6to a feeder line 'i that is in communication with suitable distributingmechanism 8. The distributing mechanism 8 includes a motor driven fan 9that is horizontally mounted above the refractory bed 3 and which isarranged to distribute the liquid fuel in a suitable spray or mistagainst the wall of the continuous recess 5.

The present invention has to do with the means for igniting the liquidfuel as it is initially discharged against the face of the hearthsegment when the distributing apparatus 8 is set in operation by thedemand for operation by the control mechanism ii (not shown in detail).

The present invention provides a practical,

eillcient and safe means for spark igniting the fuel, in whichprecautions are taken to guard against explosions.

In heretofore known liquid fuel burning devices employing spark ignitionthere is a considerable tendency for the electrodes to become shorted-bythe accumulation of carbon deposits, with the result that, in the casewhen the hearth .segments become warm or hot, the fuel, upondistribution against the hearth segment, may gasify. The carbon depositsmay be broken away by the weight of the fuel which is impinged thereon,and this will allow a spark to pass between the electrodes, with theresult that the vaporized fuel will suddenly explode with great force.It is thus obvious that precautions must be taken that the electrodes origniters will always spark at the instant when the fuel distributingmechanism is set in operation by the demand for heat. I

In the drawings different types of ignition devices are shown, any oneof which may be under control by various electric hook-ups. Thesedifferent types, however, regardless of the type of electric hook-upused, are arranged to provide safe and unfailing operation whenever thedemand for operation of the fuel burning apparatus is created.

In some cases, such as in small furnace installations, it may bedesirable to use a single .spark ignition device, whereasin other casesit may be desirable to use two or more devices.

In Fig. 1, and as shown in Figs. 5 to 10, inclusive, two such ignitiondevices are shown mounted diametrically opposite each other.

Referring to Figs. 1 to a, inclusive, each ignition device includes a.pair of electrodes 10 and 11 carried by the hearth segment 2 and spacedto obtain the best and most efficient spark.

The electrode 10 comprises a body of suitable heat resistant material,such as carborundum cement, mounted within a recess 12 formed in thesegment at the inner side thereof, the body.

being preferably recessed out in the same manner as the recess 5 toprovide continuous surfaces. The body 10 should, for the most efficientoperation of the apparatus, terminate substantially at the face of therecess 5. It is to be understood, however, that'the body may terminateslightly inwardly or outwardly of the face of the recess 5 withoutdeparting from the spirit and scope of the appended claims.

An electrode rod 13 of steel or other suitable conducting material isembedded in the body 10 and extends downwardly through the hearthsegment 2. The portion ofthe rod 13 extending beyond the segment 2 isenclosed within asuitable insulating tube 14 which preferably extendsintothe hearth segment.

The electrode 11 which. as shown in the drawings, may be in the form ofa bar of suitable heat resistant material, is mounted on asupportinghead 15 that is carried at the end of an electrode rod 16. The electroderod 16 is also mounted within an insulating tube 17 that extends througha flange 18 formed on the hearth segment 2 at the inner side thereof.The electrode 11 extends over the innermost portion of the segment 2,substantially into the recess 5, and is arranged at an angle to theradius of the segment in order that liquid fuel may be distributedwithout hindrance against the walls of the recess formed in theelectrode body 10. The insulating tubes 14 and 17 may be clamped againstrotation by means of a suitable clamp 19 arranged at the lower side ofthe segment 2.

When a single ignition device is used, such as in small furnaceinstallations, the electrode rods 13 and 16 are connected throughsuitable 'lead wires to the secondary winding of a suitable transformer.

When two or more ignition devices are used, such as in large furnaceinstallations, the ignition devices may be connected in parallel andconnected with a suitable transformer, 20, as

shown in Figs. 5, 6 and '1, or they may be connected in series andconnected with the transformer 20, as shown in Figs. 8, 9 and 10.

In the wiring diagrams Figs. 5'to 10, inclusive, the electrodes of oneignition device are designated as 10 and 11 and the correspondingelectrodes of the other ignition device are designated as 10 and. 11,the other parts being corre= spondingly numbered.

Referring to Fig. 5, the electrode 10 is connected by a suitable leadwire 21 to a pole 22 of the secondary winding 23 of the transformer 20,and the electrode 11 is connected by a suitable lead wire 24 to theother pole 25 of the secondary winding 23. In a similar manner, theelectrode 10, which corresponds to the electrode 10, is connected by alead, wire 21 to the pole 22 of the secondary winding, and the electrodeisl which corresponds to the electrode 11 by a lead wire 24 I to thepole 25 of the secondary winding. It will be noted in this hook-up thatif the electrodes of either of the ignition devices are inoperative, theother electrodes will function as soon as a demand for ignition iscreated. This installation insures the passage of a spark between theelectrodes of either one or both of the ignition devices.

Referring to Fig. 8, the electrode 10 of the on ignition device isconnected by a lead wire 26 to the pole 22 of the secondary winding, andthe electrode 10 which corresponds to the electrode 10, is connected bya lead wire 27 to the other pole 25 of the secondary winding 23. Theelectrodes 11 and 11 are directly connected with each other by means ofa lead wire 28. In this installation the two ignition devices are inseries and it will be noted that if the electrodes of one of the devicesis shorted, the current will flow 156 1,943,032 therethrough to theother device, with the result of the electrode 11 in order to obtain theproper is provided at the upper end of the electrode rod spark gap isprovided for by loosening the nut 30 and rotating the rod 16. Thestationary arrangement of the electrode 11 is not shown in the drawings,but it is obvious that this may be obtained by merely lengthening theinsulating tube 1'7 to bring it into engagement with the head 15.

Modified arrangements oi the electrodes are shown in Figs. 15 to 1'7,inclusive. In Figs. 16

and 15 the electrode rods 31 and 32 are arranged side by side at theinner side of the hearth segment 2. These electrode rods 31 and 32-aresurrounded by suitable insulators 33 and 34 which extend through anoiiset portion 36 formed at the inner side of the hearth segment 2. One

electrode 37 inthe form of a suitable block is mounted inthe segment 2in substantially the same manner as the electrode 10, and the electroderod 31 is bent over and embedded in a portion of the electrode body 3'7;The electrode 38 32 in the proper sparking position with respect to theelectrode 37.

In Fig. 1'? the electrode rods 39 and .0 are mounted in suitableinsulating tubes 41 and 42, respectively, the tube 41 being extendedinto the body of the hearth segment 2. One electrode 43 in the form of asuitable rod or bar is joined with the rod 39 and is positioned'withinan opening at formed in the segment 2 and opening at the face of thecircumferential recess 5. The electrode 43 preferably extends to andterminates at the edge of the opening 44.

The other electrode 45 is attached to the electrode rod 40 in a mannersimilar to the electrode 11 first described.

The electrodes shown in Figs. 15 and 1'7 may be connected with asuitable transformer in any of the manners previously described or inany other desired manner.

The electrodes 11, 38 and 45 shown in Figs. 4, 15 and 17, may be of anysuitable material, and furthermore may be of any suitable shape, such asa rod, bar or strap.

This invention further contemplates, in cases where desired, theprovision of means for moving one of the electrodes of each ignitiondevice relative .to the other in order to doubly insure sparking acrossthe gap between the electrodes at the time the demand for operation ofthe apparatus isv created.

One means of accomplishing this object is shown in Fig. 4. Asshown inthis view, the electrode rod 16 is made of a material having a lowironcontent and is'of greater length than the surrounding insulator tube1.7- in order that the rod 16 and consequently the electrode 11 may bemoved-relative to the tube 1'7. Movement in this case is provided bymeans of a suitable solenoid 46 surrounding the insulator tube 17, whichattracts a suitable soft iron core '16 secured to the end ofthe rod 16.In operation, the solenoid, at

the time the demand for operation of the apps ratus is created, movesthe electrode 11 from its normal position to the sparking position shownin solid outline in Fig. 4. As'soon as the sparking period isterminated, the supply 01' electrical energy to the'solenoid is cut offand the electrode 11 then drops back by gravity to the normal positionshown in broken outline in Fig. 4. The electrode rod 16 may be ofsufiicient weight as to drop back to the inoperative position or, ifdesired, ad-- ditional weights may be attached to the rod 16 or in somecases a spring arrangement may be pro vided to cause the rod.16 andelectrode 11 to assume the position shown in broken outline.

' A suitable cap 47 may be arranged over-the head 15 to telescope withthe projecting portion of the insulator tube 17 in order to excludedirt,

liquid fuel, and other foreign matter from the rod v16. Suitable guidesare provided to prevent turning movement of the electrode rod 16relative to the axis of the tube 17, and this maybe accomplished in anydesired manner such as forming depressions as in the upper end of thetube 17 which may receive guide ribs 49 formed on the inner surface ofthe cap 4'7.

In Figs. 11 and 12 a modified arrangement is shown for moving theelectrode 11 relative to the electrode 10. In-this arrangement theelectrode rod 16 and insulating tube 1'7 are rigidly held togetheragainst relative movement, and the complete electrode assembly ismounted for bodily tilting movement transversely of the axis thereof.

One means for accomplishing this tilting move ment is to provide asleeve 50 about the tube 17, which has oppositely disposed pivot pins 51thereon arranged to seat in the depressions 52 formed in the hearthsegment 2. A suitable protector 53 'is provided to protect ,the pivotpins 51 from dirt and the like. In the normal position, the electrodeassembly is maintained in a vertical position by gravity, in which1))Sltl0l'l the electrode 11 is .out of its sparking position as shownin solid outline in Fig. 11. A suitable weighti'v may be mounted on thetube 17 to insure a vertical position of the electrode assembly.

In order to pivotally move the electrode assembly to-the operativeposition where a spark may be passed between the electrodes 16 and 11, asolehold 54 or other suitable means may be employed to attract a core 54carried by a sleeve 55 that is clamped to the insulator tube 1'7, andthereby swing the assembly about the pins 51 as axes to the desiredsparking position indicated in broken .outline in Fig, 11. Means otherthan the electro: magnets 54 may, However, be employed to provide thedesired pivotal movement.

In Fig. 13, electromagnet means 56 is shown for causing a rotationalmovement of the electrode rod 16 in order to movethe electrode 11relative to the electrode 10. As shown in Fig. 14, an arm 57. maybe'attached to the lower end of the rod 16 which carries a core 5'7 thatmay be attracted by the magnet means 56. Means other than the magnet 54may also be employed to impart the desired swinging movement to the and13, the electrode 11 is movable with respect to the electrode 10 afterthe ignition period is over. Assuming for the purposes of illustrationthat the electrodes 10 and 11 are sparking and that they may becomeshorted by reason of carbon deposits, then they will no longer spark.The

' current may, by the operation of the system, then be cut off by thecontrol mechanism, and as soon as this occurs the electrode 11 bodilymoves relative to the electrode 10 with the result that the carbondeposit is broken.

Now assuming that the electrode 11 is in its normal position and acarbon deposit has accumulated on the electrodes to such an extent as toclose the gap, then in this case as soon as the demand for ignition iscreated, the electrode' 11 moves and breaks the carbon deposit, with theresult that the electrodes will spark immediately and coincident withthe starting of the liquid fuel distributing mechanism 8,'and willimmediately ignite the fuel that is dispelled against the hearth segment2, and incidentally against the electrode 10. i

In constructions heretofore known, the electrodes may become shorted byreason of the deposit of carbon across the spark gap when the system isnormally inoperative, with the result quantity may collect on the carbondeposit tocause the deposit to break away from the electrodes. Theresult is obvious. since the electrodes 1 will then spark and as aresult the gasified fuel will be ignited and produce a violentexplosion, the consequences of which may be very disastrous.

It is thus seen that the device of the present invention will overcomethe disadvantages heretofore known, and will provide a safe-andefficient ignition system'for liquid fuel burning apparatus.

Several different methods of connecting the solenoid 46 with a source ofelectrical energy may be employed.

Referring to Fig. 5 which is a wiring diagram for the apparatus when twoignition devices are employed. the solenoid coils 46 and 46' may beconnected in series with the transformer 20. The solenoid coils 46 and46': of the two ignition devices are connected in series by the wire 59,theremaining end of the one coil 46 being connected by a wire 60 intothe hot line 61 of the electrical energy supply, and the'other solenoidcoil 46 being connected by a wire 62 to, the primary coil 63 of thetransformer. In this circuit it will be seen that if either of thesolenoid coils becomes inoperative or burned out, the supply of energyto the other and to the electrodes is immediately cut off. If only theone ignition device is used the wire 59 may be connected into thecircuit in the same manner as the wire62.

Referring to Fig. 6, the solenoid coils 46 and 46 are connected inparallel with the energy or temperature responsive wires 65 and 66directly with the main supply lines 61 and 64, respectively, and thesolenoid coil 46'- is connected by wires 65 and 66' directly with themain supply lines 61 and 64, respectively. In this circuit theelectrodes are all connected in parallel with the secondary winding ofthe transformer. It is obvious that if either of the solenoid coilsburns out or is broken the other will properly function. Referring toFig. '1, the solenoid coils 46 and 46" are connected in multiple serieswith the transformer 26. The coils 46 and 46'- are con-' nected togetherby the wires 6'? and 68, the-wire 68 being connected into the hot supplyline 61 in advance of the transformer by the wire 69,

function independently of each other, and that each ignition device willfunction independently of the other.

In Figs. 8. 9 and 10, the circuits for the solenoids are the same as thecircuits for the sole-- noids in Figs. 5, 6 and 7. respectively, theonly difference in the circuits being that the electrodes in Figs. 8, 9and 10 are in series instead of in parallel, as shown'in Figs. 5, '6 and'7.

It is obvious that other combinations of circuits for the ignitiondevices and the solenoids may be employed, if desired. v

Many advantageous features are present in this invention that are notpresent in liquid fuel burning devices heretofore known, and it ispossible in the use of the various structuresand circuits thereforeshown and described herein, to use a spark ignition apparatus for fuelburners which is eilicient in operation and which can be safely usedwithout danger of explosions resulting from the deposit of carbon on theelectrode.

It is to be understood that in some cases the electrodes may both berigidly held against relative movement and that in other cases it may bedesirable to mount one of the electrodes for movement relative to theother, as previously described. a

Aside from the specific embodiments of the herein shown and describedinvention, it will be understood that numerous details of theembodiments may be altered or omitted without departing from the spiritand scopev of this invention, and that I do not desire to limit theinvention to-the exact constructions herein set forth, as I desire toclaim the invention broadly as well as specifically as indicated in theappended claims.

What I claim is:

1. In a liquid fuel burning apparatus, a pair of spaced ignitionelectrodes providing an air gap across which a spark may be passed toignite the fuel, and means for moving one of said electrodes relative tothe other and into an eflicient sparking position spaced from the otherwhen the fuel is to be ignited. and for maintaining said last mentionedelectrode in such position during the ignition period.

2. In a liquid fuel burning apparatus, a pair of spaced ignitionelectrodes providing an air gap for maintaining said electrodes in suchrelation during substantially the entire ignition period. 1

3. In a liquid fuel burning apparatus, a pair of spaced ignitionelectrodes providing an air gap across which a spark may be passed toignite the fuel, electrical means for bodily moving one of saidelectrodes'relative-to the other at the time ignition of the fuel isdesired to bring said electrodes into spaced sparking relation and formaintaining said electrodes in such relation during substantially theentire ignition period, and means for returning the said one electrodeto its initial position after the ignition period is terminated.

4. In a liquid fuel burning apparatus, a pair of spaced ignitionelectrodes providing an air gap across which a spark may be passed toignite the fuel, means for bodily tilting one of said electrodesrelative to the other at the time ignition of the fuel is desired tobring said electrodes into spaced sparking relation and for maintainingsaid electrodes in such relation during substantially the entireignition period, and means for returning the said one' electrode to itsinitial position after the ignition period is terminated.

5. In a liquid fuel burning apparatus, a pair of spaced ignitionelectrodes providing an air gap across which a spark may be passed toignite the fuel, means for rotating one of said electrodes relative tothe other at the time ignition of the fuel is desired to bring saidelectrodes into spaced sparking relation and for maintaining saidelectrodes in such relation during substantially the entire ignitionperiod, and means for returning the said one electrode to its initialposition after 6. In a liquid fuel burning apparatus, ignition meanscomprising a hearth member, an ignition electrode mounted on said hearthmember and arranged to have liquid fuel discharged against the same, asecond ignition electrode spaced from said first electrode, a movablesupport for said second. electrode, and electrical means forlongitudinally moving said support to bring said electrade into propersparking position spaced from the first electrode at the time ignitionof the fuel is desired and for holding said second electrode in suchposition during the ignition period, said support being movable back toits initial position after the ignition period is terminated.

'7. In a liquid fuel burning apparatus, ignition means comprising ahearth member, an ignition electrode embedded in said hearth membersubstantially flush with the surface thereof and arranged to have liquidfuel discharged against by said tube for longitudinally-moving saidsupport to bring said electrode into proper sparking position at thetime ignition of the fuel is desired for holding the same in suchposition during substantially the entire ignition period, said supportbeing movable back to its initial position after the ignition period isterminated.

8. In a rotary oil burning apparatus, including an endless hearth memberhaving an upstanding portion for intercepting the path of a projectedstream of oil, and ignition means for'igniting the oil intercepted bysaid upstanding portion, said ignition means including an electrodefixedly embedded in said hearth member and having a face substantiallyflush with the face of said upstanding portion, a second electrodespaced from the first electrode and electrical means to bodily move saidsecond electrode into proper sparking position at the start of theignition period and to maintain the same in such position duringsubstantially the entire ignition period.

9. In a liquid fuel burning apparatus, a pair of spaced ignitionelectrodes providing an air gap across which a spark may be passed toignite the fuel during an ignition period, means for moving'one of saidelectrodes relative to the other and into an eflicient sparking positionspaced from the other and for maintaining the same in such positionduring substantially the entire ignition period, and means for movingthe said one electrode to its original position afterithe'ig'nitionperiod is terminated.

10. In a liquid fuel burning apparatus, a pair of ignition electrodesspaced from each other. at all times for ignitingfuellduring an ignitionperiod, one of said electrodesibeing fixed, and means for moving theother of said electrodesrelative to the fixed electrode into spacedsparking relation at the beginning .of the ignition period.

11. In a liquid fuel .burning apparatus, a pair of ignition electrodesspaced from each other at all timesfor igniting the fuel during anignition period by means of a spark passed between the same, one of saidelectrodes being fixed and means for moving the other of said electrodesrelative to the fixed electrode after the ignition pe; riod isterminated to increase the space therebetween.

WILLIAM J. SMITH.

